Robert Montgomerie

• PhD, BSc
• Emeritus Professor at Queen's University

STUDY QUESTION Has there been variation in semen quality among men applying to be sperm donors (i.e. donor candidates) in Denmark in recent years (2017–2022)? SUMMARY ANSWER The motile sperm concentration and total motile sperm count (TMSC) in ejaculates—both measures of sperm quality—declined by as much as 22% from 2019 to 2022. WHAT IS KNOWN AL...

Climate change has resulted in a marked advancement in the breeding phenology of many bird species. Since the timing of many monitoring programs is based on calendar dates, changes in the timing of birds’ breeding seasons may result in a mismatch with the census period. Using data from a long-term population study of Common Murres (Uria aalge; Comm...

Study question Has sperm quality among candidate sperm donors in Denmark changed in recent years (2017-2022)? Summary answer Although sperm concentration of candidate donors did not change, sperm quality (motility) declined by ∼35% after controlling for age and other potential confounds. What is known already Questions remain about whether human...

Elaborate avian feather ornaments have proven to be enigmatic because their function is often unclear, even though they are used in courtship and social displays. Male and female Whiskered Auklets Aethia pygmaea display on their faces four elaborate feather ornaments that serve both courtship and mechanosensory functions: three bilateral pairs of w...

Background Previous research has shown that the type and duration of erotic material that men have access to during masturbation can influence semen parameters. To our knowledge, the use of virtual reality (VR) headsets to present erotica has not previously been studied. We reasoned that, because VR can provide a more immersive experience to the us...

Casey Albert Wood’s The fundus oculi of birds, published in 1917, was the culmination of his decade-long study of the eyes of about a hundred bird species across the avian phylogeny. Wood was a professional ophthalmologist who, during his spare time, was drawn to the study of birds’ eyes because of their exceptional visual acuity. His stated goal w...

Melinda Pruett-Jones In 2018, the American Ornithological Society (AOS) established the Peter R. Stettenheim Service Award, intended to carry on the tradition of the Cooper Ornithological Society Honorary Member Award, one of the oldest awards in ornithology. The Peter R. Stettenheim Service Award recognizes an individual well established in their...

Nearly seventy years ago, Preston (1953) (The Auk 70:160) published a pioneering study in which he provided formulae for the shapes of birds’ eggs. One of these formulae is universal in that it provides an almost perfect representation for all eggs, even pyriform ones, and is better than all other formulae published since. This essentially perfect...

Both sexes of Whiskered Auklets (Aethia pygmaea) display the most elaborate feather ornaments of any seabird: a slender black forehead crest, and 3 bilaterally symmetrical pairs of white facial plumes (superorbital, suborbital, and auricular). We studied patterns of ornament variation in 796 banded individuals (147 of known sex, 254 of known age fr...

Since the late 1600s it has been assumed that the Great Auk Pinguinus impennis was similar to the Common Guillemot Uria aalge and Brünnich’s Guillemot U. lomvia in having a single, central brood patch. Through the examination of eight mounted museum specimens, we show that this is incorrect and that like its closest relative the Razorbill Alca tord...

We studied the shapes of eggs from 955 extant bird species across the avian phylogeny, including 39 of 40 orders and 78% of 249 families. We show that the elongation component of egg shape (length relative to width) is largely the result of constraints imposed by the female's anatomy during egg formation, whereas asymmetry (pointedness) is mainly a...

We studied the ground colors and maculations of 161 Common Murre (Uria aalge) eggs laid by 43 females in 3 small breeding groups on the cliffs of Skomer Island, Wales, in 2016–2018. Both the colors and maculations varied much more among than within females, providing quantitative evidence for the egg traits that might facilitate the parents’ abilit...

Life history theory predicts that females may increase reproductive allocation with advancing age as the probability for future reproduction diminishes. In iteroparous fishes, increasing age is usually accompanied by increasing fecundity but evidence of increasing offspring quality is less consistent. We examined the developmental rate and survival...

The Taylor White Collection of paintings from the 1700s, held at the McGill University Library, includes 661 paintings that illustrate 832 birds from around the world. With illustrations of 443 species in 30 avian orders, this collection represents a substantial proportion of the bird species known at the time and is one of the most comprehensive a...

In the three decades, since Birkhead and Møller published Sperm competition in birds (1992, Academic Press) more than 1000 papers have been published on this topic, about half of these being empirical studies focused on extrapair paternity. Both technological innovations and theory have moved the field forward by facilitating the study of both the...

Members of the seabird family Procellariidae (albatrosses, petrels and shearwaters) typically produce a single-egg clutch. Two-egg clutches have been recorded occasionally in some of those species, but it is not known whether they were laid by a single female. In this study we examined eight two-egg clutches of the Fulmar Fulmarus glacialis in the...

To date, the majority of authors on scientific publications have been men. While much of this gender bias can be explained by historic sexism and discrimination, there is concern that women may still be disadvantaged by the peer review process if reviewers’ biases lead them to reject publications with female authors more often. One potential soluti...

Statistical Supplement. Code and output of all statistical analyses in the article.

To date, the majority of authors on scientific publications have been men. While much of this gender bias can be explained by historic sexism and discrimination, there is concern that women may still be disadvantaged by the peer review process if reviewers' unconscious biases lead them to reject publications with female authors more often. One pote...

The adaptive significance of avian egg shape is a long-standing problem in biology. For many years, it was widely believed that the pyriform shape of the Common Murre (Uria aalge) egg allowed it to either "spin like a top" or "roll in an arc," thereby reducing its risk of rolling off the breeding ledge. There is no evidence in support of either mec...

A recent broad comparative study suggested that factors during egg formation — in particular ‘flight efficiency’, which explained only 4% of the interspecific variation — are the main forces of selection on the evolution of egg shape in birds. As an alternative, we tested whether selection during the incubation period might also influence egg shape...

The European Honey-buzzard (Pernis apivorus) was first accurately described and clearly distinguished from the Common Buzzard (Buteo buteo) by Francis Willughby and John Ray in their Ornithology, originally published in Latin in 1676. Alfred Newton’s statement that Pierre Belon had described the species over a century earlier is not entirely correc...

Huge numbers of Common Guillemot (Uria aalge) eggs were harvested by local men known as “climmers” (climbers) at Bempton Cliffs, Flamborough, Yorkshire, until 1954 when egg collecting became illegal. Guillemot eggs are more variable in colour and pattern than those of any other bird. Egg collectors (oologists) particularly favoured sets of unusuall...

Perchlorate (ClO4-) contamination has been reported in ground and surface waters across North America. However, few studies have examined the effects of prolonged exposure to this thyroid hormone disrupting chemical, particularly at environmentally relevant concentrations in lower vertebrates, such as amphibians. The aim of this study was to examin...

Recent comparative studies of several taxa have found that within-species variation in sperm size decreases with increasing levels of sperm competition, suggesting that male-male gamete competition selects for an optimal sperm phenotype. Previous studies of intraspecific sperm length variation have all involved internal fertilizers where some other...

During the 1830s, Charles Thorold Wood jun. and his younger brother Neville Wood, published, separately, three books and a series of articles dealing with two ornithological subjects: the common and scientific names of birds, and the cataloguing of publications. Probably following William Swainson's lead, the Woods were enthusiastic about standardi...

Courtship displays may serve as signals of the quality of motor performance, but little is known about the underlying biomechanics that determines both their signal content and costs. Peacocks (Pavo cristatus) perform a complex, multimodal "train-rattling" display in which they court females by vibrating the iridescent feathers in their elaborate t...

Datasets and R script. (ZIP)

Sources of shaking frequencies and scaling relationships used in Fig 2 of the main text. (DOCX)

Audio analysis and characterization of sound production. (DOCX)

Calculation of mechanical properties of the feather rachis. (DOCX)

Statistical supplement. (PDF)

Statistical models of morphology and train-rattling frequency. (DOCX)

Real-time and slow motion video of peacock courtship displays. https://www.youtube.com/watch?v=voPTJ9KKsoY Adult peacocks court peahens by vibrating the erect tail and elongated upper tail covert feathers during their train-rattling displays. Wing-shaking is also performed during courtship. Slow-motion clips of train-rattling peacocks demonstrate t...

Peacocks perform train-shivering to erect and spread their train feathers. https://www.youtube.com/watch?v=zatLFC5wVn0 Videos are shown from the front and side, in real-time and slow motion. (MP4)

Feather vibrational resonance. (DOCX)

Comparison of eyespot motion and peafowl visual acuity. (DOCX)

Subadult peacock train-rattling and peahen covert-rattling displays. https://www.youtube.com/watch?v=nCaZ0wYpJPc Subadult peacocks (i.e., those with trains < 1 meter in length) also perform train-rattling displays. Peahens perform a similar behavior that we call covert-rattling, in which they vibrate their tails and upper tail coverts. (MP4)

Real-time and high-speed video of a peacock eyespot feather vibrated by a mechanical shaker. https://www.youtube.com/watch?v=yTfk5Izepfo When peacock eyespot feathers are vibrated at 25.6 Hz using a mechanical shaker, the eyespot remains relatively stationary compared to the rapidly moving and flickering loose green barbs. This motion mimics what i...

Growth of peacock feathers. (DOCX)

Model of resonant properties of the tail. (DOCX)

In this study, we investigated two potentially important intersexual postcopulatory gametic interactions in a population of chinook salmon (Oncorhynchus tshawytscha): (i) the effect of female ovarian fluid (OF) on the behaviour of spermatozoa during fertilization and (ii) the effects of multilocus heterozygosity (MLH) (as an index of male quality)...

Background: Recent comparative studies of several taxa have found that within-species variation in sperm size decreases with increasing levels of sperm competition, suggesting that male-male gamete competition selects for an optimal sperm phenotype. Previous studies of intraspecific sperm length variation have all involved internal fertilizers wher...

Background: Recent comparative studies of several taxa have found that within-species variation in sperm size decreases with increasing levels of sperm competition, suggesting that male-male gamete competition selects for an optimal sperm phenotype. Previous studies of intraspecific sperm length variation have all involved internal fertilizers wher...

Table of contents R code and analyses to accompany: Stewart, Wang, and Montgomerie. 2016. Extensive variation in sperm morphology in a frog with no sperm competition. BMC Evolutionary Biology This &ile contains all of the R code and output for statistics included in and referred to in this paper. The analyses are divided into numbered sections with...

image Mol. Reprod. Dev. 83: 8–11, 2016. © 2015 Wiley Periodicals, Inc .

Two recent studies provide provocative experimental findings about the potential influence of kin recognition and cooperation on the level of sexual conflict in Drosophila melanogaster. In both studies, male fruit flies apparently curbed their mate-harming behaviours in the presence of a few familiar or related males, suggesting some form of cooper...

Differences in body size are widely thought to allow closely related species to coexist in sympatry, but body size also varies as an adaptive response to climate. Here, we use a sister lineage approach to test the prediction that body size differences between closely related species of birds worldwide are greater for species whose ranges are sympat...

Closely related species of birds often differ markedly in their color patterns. Here we examine the influence of breeding-range overlap (breeding sympatry) on the evolution of color pattern differences in a sample of closely related bird species. We used a sister-lineage method to analyze 73 phylogenetically independent comparisons among 246 specie...

The discovery that extrapair copulation (EPC) and extrapair paternity (EPP) are common in birds led to a paradigm shift in our understanding of the evolution of mating systems. The prevalence of extrapair matings in pair-bonded species sets the stage for sexual conflict, and a recent focus has been to consider how this conflict can shape variation...

Gonad size and shape asymmetries are particularly common in birds. Although some obvious size and shape differences between the left and right testes in birds were first documented more than a century ago, little is known about what influences the variation across species in either the degree or the direction of these asymmetries. Here we show that...

Condition-dependent mate choice is thought to affect the strength and direction of sexual selection. Although there is ample evidence of this from studies that experimentally manipulate female condition, few studies to date have examined condition dependence of natural mate choice wherein females interact with a pool of available males. We examined...

Abstract Theory holds that dishonest signaling can be stable if it is rare. We report here that some peacocks perform specialized copulation calls (hoots) when females are not present and the peacocks are clearly not attempting to copulate. Because these solo hoots are almost always given out of view of females, they may be dishonest signals of mal...

Video Self-Modeling (VSM) is an intervention that allows individuals to observe exemplary instances of their own behaviour on video in order to increase the probability of that behaviour occurring again. VSM has been used to teach and strengthen various behaviours, however, little research has been conducted on VSM as an intervention to increase or...

Each of the multicolored eyespots (ocelli) on the peacocks (Pavo cristatus) train is a complex structure with a purple-black center surrounded by concentric blue-green and bronze-gold regions. To investigate the influence of all 3 of these colors on male mating success, we used a physiological model of peafowl vision to quantify those colors as fem...

Social selection influences the evolution of weapons, ornaments and behaviour in both males and females. Thus, social interactions in both sexual and non-sexual contexts can have a powerful influence on the evolution of traits that would otherwise appear to be detrimental to survival. Although clearly outlined by West-Eberhard in the early 1980s, t...

Ornaments, weapons and aggressive behaviours may evolve in female animals by mate choice and intrasexual competition for mating opportunities-the standard forms of sexual selection in males. However, a growing body of evidence suggests that selection tends to operate in different ways in males and females, with female traits more often mediating co...

Recent studies have reported conflicting evidence for the influence of train-feather eyespots on the mating success of peacocks, Pavo cristatus. In this study we address this controversy, using observation and experiment to evaluate the effect of train morphology and the number of eyespots displayed during courtship on female choice. We show first...

A recent hypothesis suggests that birds’ blue-green egg colors may be a sexually selected signal of female (and potentially nestling) quality that males use to make parental investment decisions. While there is some empirical support for this idea, both theory and observations question its validity. To test this hypothesis experimentally, we examin...

The online supplement to this paper presents some additional details of our “Methods” and “Results”, especially to provide full details of the statistical methods used and the models evaluated using the IT approach.

Theoretical models predict that individual males will increase their investment in ejaculates when there is a risk of sperm competition. Because the production of ejaculates is assumed to be energetically costly, only those males in good physical condition should be capable of producing ejaculates of high quality. We studied ejaculate investment (r...

Arising from M. A. Nowak, C. E. Tarnita & E. O. Wilson 466, 1057-1062 (2010); Nowak et al. reply. Nowak et al. argue that inclusive fitness theory has been of little value in explaining the natural world, and that it has led to negligible progress in explaining the evolution of eusociality. However, we believe that their arguments are based upon a...

Though the rock ptarmigan, Lagopus mutus (Montin, 1776), is a relatively common breeding bird in arctic regions worldwide, several Nearctic insular populations have become extinct or threatened in the past 250 years. In this study, we use patterns of DNA sequence variation in the mitochondrial control region and a nuclear intron (GAPDH) to reexamin...

Time budgets of house sparrows (Passer domesticus) foraging at a bird feeder revealed that the time an individual allocated to scanning for predators was negatively correlated with the size of the foraging group. The frequency of both aggressive and scanning bouts per individual did not vary significantly with group size. Reduced scanning time by i...

Parental Baird's sandpipers increased the intensity of their nest defence through the incubation period. One member of each pair was relatively tame, staying closer to the human "predator" and engaging in more risky behaviours than the other, but both parents increased risk taking as the incubation period progressed. Members of this High Arctic pop...

We used a field experiment, population modeling, and an analysis of 30 years of data from walleye (Sander vitreus; a freshwater fish) in Lake Erie to show that maternal influences on offspring survival can affect population dynamics. We first demonstrate experimentally that the survival of juvenile walleye increases with egg size (and, to a lesser...

Certain loud calls made by female red junglefowl and Lapland longspurs are given most frequently immediately after egg laying, when a copulation should have the highest probability of fertilizing the next egg to be laid. In these species there is considerable male-male interaction for access to fertilizable females, and males are attracted to or fo...

This chapter describes some milestones in the history of sperm biology—especially those concerned with the evolution of spermatozoa—and highlights the contributions of some of the personalities involved in the major discoveries. It focuses mainly on the period from the 1670s when Antonie van Leeuwenhoek (1678) discovered spermatozoa to the 1970s wh...

Interest in female ornamentation has burgeoned recently, and evidence suggests that carotenoid-based female coloration may function as a mate-choice signal. However, the possibility that females may signal status with coloration has been all but ignored. Bill coloration of female American goldfinches (Spinus tristis) changes seasonally, from dull g...

We describe a unique, hand-coloured copy of Ray’s (1678) The Ornithology of Francis Willughby that was apparently presented to Samuel Pepys between 1684 and 1686 during his presidency of the Royal Society. Somehow, this volume was not catalogued as part of Pepys’s famous library, and fell into private hands until, in 1924, it was purchased for the...

Sperm traits of externally fertilizing fish species are typically measured in fresh (or salt) water, even though the spawning environment of their ova contains ovarian fluid. In this study, we measured sperm traits of Chinook salmon (Oncorhynchus tshawytscha (Walbaum in Artedi, 1792)) in both fresh water and dilute ovarian fluid at 10 and 20s posta...

Latitudinal variation in patterns of evolution has fascinated biologists for over a century, but our understanding of latitudinal differences in evolutionary processes-such as selection and drift-remains limited. Here, we test for, and find, accelerated evolution of color patterns in bird taxa that breed at higher latitudes compared with those bree...

In many tropical bird species, both males and females maintain elaborate plumage traits. Although there is considerable evidence that many male plumage traits function as status signals that convey information about fighting ability, less is known about status signaling in females. We tested whether the carotenoid-based orange breast coloration of...

Previous work has demonstrated that genomic incompatibilities work together with ecologically divergent selection to promote and maintain reproductive isolation between incipient species (dwarf and normal) of lake whitefish (Coregonus clupeaformis (Mitchill, 1818)). Whitefish spawn in groups with external fertilization, which creates conditions for...

We studied two courtship displays of male peafowl (Pavo cristatus), focusing particularly on male orientation relative to the position of the sun. During the “wing-shaking” display, females were generally behind the displaying male, and male orientation with respect to the position of the sun was not significantly different from random. However, du...